The present invention relates to an image forming apparatus for forming an image on a recording material, hereinafter referred to as sheet, supplied from a supplier.
There are occasions when copy sheets (i.e. sheets on which images are formed) from a copying machine are stapled into booklets, and a stapler for such use is known and used. To achieve the binding process a finisher is known and used. There are another occasions when a mark "Confidential" or "Circulate" is stamped on copy sheets, and a stamping device for such use is known and used. The stapler, stamping device and so on are generally called a finisher. The known finishers are designed to handle copy sheets having a predetermined size which are stacked in such a number as not to exceed the capacity of the finisher.
However, there are problems involved in operating the known finishers; for example:
(1) When the image forming apparatus is equipped with a manual sheet inserting section, it may happen that unsuitable sheets such as those out of size for the finishing process are supplied.
(2) There are occasions when the operation of the finisher must be prohibited for particular reasons. For example, when several copy sheets are separately needed, they must be obtained without the finishing process in order to avoid a jamming of sheets, an error on the finisher and wasting staples, etc.
There are another occasions when the manual sheet insertion mode must be prohibited during the finishing mode.
In these cases the associated operations of the copying operation on sheets from the manual sheet insertion section and the finishing process, particularly the stapling operation, must be prohibited.